These maps show
the published TriNet PGV ShakeMaps for Landers and Northridge. Contours and
observed values are given in units of cm/s.The Landers map appears to be controlled by the near-fault Lucerne
Valley Station producing a bull's-eye in the shakemap.The Northridge map shows areas of strong
ground motion due to both directivity and a combination of directivity and
basin amplification.It is noted that
the numbers of stations used in each of these maps is greater than the number
of stations likely to be available in the presently operating TriNet
shakemap.Both maps will be revisited
when we discuss the effect of station density and present our combined
data/model shakemap results.